Showing papers on "Hydrazine published in 2013"
TL;DR: In this article, a transition metal-dinitrogen-bridged dimolybdenum complex bearing two PNP-type pincer ligands was used as a catalyst for the conversion of molecular dinitrogen into ammonia or ammonia equivalent, silylamine.
316 citations
TL;DR: The probe is successfully demonstrated to enable the detection of hydrazine in live cells and results in the recovery of the ESIPT by removal of a free HBT moiety through subsequent substitution, cyclization, and elimination processes.
232 citations
TL;DR: In this article, a simple chemical method using hydrazine hydrate as the main reagent was firstly used to modify graphite felt as cathode for efficient electro-Fenton process.
191 citations
TL;DR: The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield as mentioned in this paper, which leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes.
Abstract: The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF–ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 μM), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.
184 citations
TL;DR: In this article, a new electrocatalyst, Au-SH-SiO 2 nanoparticles immobilized on the metal-organic frameworks (MOFs), was synthesized and characterized by scanning electron microscopy (SEM), the TEM and cyclic voltammetry (CV).
182 citations
TL;DR: In this article, Meglumine, a bio-based chemical, was demonstrated to be a highly efficient and reusable catalyst for the synthesis of a series of pyranopyrazole derivatives via a one-pot, four-component reaction of carbonyl compound or isatin, hydrazine hydrate, malononitrile, and β-keto ester in EtOH-H2O.
140 citations
TL;DR: Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates.
Abstract: Kinetics studies with structurally varied aldehydes and ketones in aqueous buffer at pH 7.4 reveal that carbonyl compounds with neighboring acid/base groups form hydrazones at accelerated rates. Similarly, tests of a hydrazine with a neighboring carboxylic acid group show that it also reacts at an accelerated rate. Rate constants for the fastest carbonyl/hydrazine combinations are 2-20 M(-1) s(-1), which is faster than recent strain-promoted cycloaddition reactions.
134 citations
TL;DR: In this paper, a platinum-modified Ni/Al2O3 catalysts were tested in the decomposition of hydrous hydrazine to H2 with a high selectivity and a high activity under mild conditions.
128 citations
TL;DR: A novel hydrogen peroxide (H2O2) and hydrazine sensor based on low-cost poly(vinylpyrrolidone)-protected silver nanocubes (PVP-AgNCs) exhibited good reproducibility, selectivity and stability and might be attributed to the enhanced electrochemical sensing property of well-defined PVP- AgNCs with rich {100} facets.
121 citations
TL;DR: In this article, the structure and activity of nanocatalysts focusing on the structure-activity relationship for selective hydrogen generation from hydrous hydrazine was discussed focusing on their properties and properties.
118 citations
TL;DR: A new NIR fluorescent probe for monitoring hydrazine in blood samples and live cells was designed and synthesized.
Abstract: A new NIR fluorescent probe for monitoring hydrazine in blood samples and live cells was designed and synthesized.
TL;DR: Amorphous Ni0.9Pt0.1/Ce2O3 nanoparticles with low noble-metal content have been facilely synthesized by a co-reduction route within 10 min at room temperature under ambient atmosphere as discussed by the authors.
Abstract: Amorphous Ni0.9Pt0.1/Ce2O3 nanoparticles with low noble-metal content have been facilely synthesized by a co-reduction route within 10 min at room temperature under ambient atmosphere. The resultant Ni0.9Pt0.1/Ce2O3 nanoparticles were successfully applied as a highly efficient catalyst for rapid and complete conversion of hydrous hydrazine. A high initial turnover frequency value of 28.1 h−1 for Ni0.9Pt0.1/Ce2O3 nanoparticles is achieved with 100% H2 selectivity at 298 K. Moreover, the amorphous Ni0.9Pt0.1/Ce2O3 catalyst obtained due to the addition of Ce2O3 demonstrates much better activity and much lower activation energy than that of the crystalline Ni0.9Pt0.1. The development of the improved performance and low-cost catalyst is a promising step towards the application of hydrous hydrazine as a hydrogen storage material.
TL;DR: A new series of N-acetyl and N-formyl-pyrazoline derivatives 6 and 7-8 showed remarkable antitumor activity against cancer cell lines, with the most important GI50 values ranging from 0.13 to 0.99 μM.
TL;DR: In this paper, the activation of NH2NH2 as a transfer hy- drogenation agent was shown to cleanly and selectively reduce alkyl nitro compounds into correspond- ing amines in the presence of 4 equivalents of hydrazine.
TL;DR: A gas chromatography-mass spectrometric method has been established for the determination of hydrazine in drinking water and surface water and the accuracy was in a range of 95-106%, and the precision of the assay was less than 13% in water.
TL;DR: The highly selective chemosignaling behaviors for hydrazine by a reaction-based probe of dichlorofluorescein and resorufin acetates were investigated andHydrazine signaling in tap water was tested.
Abstract: The highly selective chemosignaling behaviors for hydrazine by a reaction-based probe of dichlorofluorescein and resorufin acetates were investigated. Hydrazinolysis of latent dichlorofluorescein and resorufin acetate fluorochromes caused prominent chromogenic and fluorescent turn-on type signals. The probes selectively detected hydrazine in the presence of commonly encountered metal ions and anions as background. Dichlorofluorescein and resorufin acetates selectively detected hydrazine with detection limits of 9.0 × 10−8 M and 8.2 × 10−7 M, respectively. Furthermore, hydrazine was selectively detected over other closely related compounds, such as hydroxylamine, ethylenediamine, and ammonia. As a possible application of the acetate probes, hydrazine signaling in tap water was tested.
TL;DR: In this paper, the authors provide a summary of the hazards of hydrazine and its aqueous solutions and an understanding of the important role dilution plays in increasing the inherent safety and environmental risk.
TL;DR: Functionalized arylhydrazines are of widespread importance as intermediates in the syntheses of nitrogen-containing heterocycles and these heterocyclic motifs are prevalent structural elements in numerous compounds of significant biological/medicinal value.
Abstract: Continuous flow or batch reactions of the arylhydrazines, formed in the first step, with β-diketones, benzaldehyde and ketones allows the synthesis of pyrazoles, hydrazones, and indoles.
TL;DR: In this paper, a series of Ni-based catalysts using a simple chemical reduction method and their performance in promoting the decomposition reaction of hydrazine monohydrate (N2H4·H2O) was reported.
Abstract: The synthesis of low-cost catalysts with favorable properties of both catalytic activity and hydrogen selectivity is highly desirable for developing a hydrous hydrazine-based hydrogen generation system. In this paper, we report the synthesis of a series of Ni-based catalysts using a simple chemical reduction method and their performance in promoting the decomposition reaction of hydrazine monohydrate (N2H4·H2O). Our study found that the NiB catalyst possesses poor catalytic activity towards the decomposition of N2H4·H2O. But upon incorporation of Mo and La elements, the catalytic performance of the resulting catalysts was remarkably improved for both catalytic activity and hydrogen selectivity. A combination of phase/microstructure/chemical state analyses was conducted to gain insight into the property improvement arising upon incorporation of a Mo or La element. The NiMoB–La(OH)3 catalyst with an optimal composition enables rapid and complete decomposition of N2H4·H2O with 100% H2 selectivity in an alkaline solution at mild temperatures. The development of high-performance and noble-metal-free catalysts may promote the application of N2H4·H2O as a promising hydrogen storage material.
TL;DR: Am ammonia borane is introduced, a versatile reducing agent for graphene oxide (GO) reduction in both aqueous and organic solvents; it is nontoxic and more effective than hydrazine.
TL;DR: In this paper, a new fluorescent and colorimetric probe based on the reaction and intramolecular charge transfer (ICT) effect is designed and synthesized, which can detect hydrazine in a wide concentration range because of the blunted sensing functional group.
TL;DR: The Ni(OH)2-MnO2 modified electrode exhibited good sensitivity, stability, and reproducibility in hydrazine sensing and was optimized to obtain the best peak potential and current sensitivity.
TL;DR: Aerobic recycling: A catalytic amount of a hydrazine reagent is sufficient to promote Mitsunobu reactions in the presence of triphenylphosphine, an iron catalyst, and air.
Abstract: Aerobic recycling: A catalytic amount of a hydrazine reagent is sufficient to promote Mitsunobu reactions in the presence of triphenylphosphine, an iron catalyst, and air. The active form of the catalyst, an azo species, can be readily generated by iron-catalyzed aerobic oxidation. MS = molecular sieves, Pc = phthalocyanine.
TL;DR: In this paper, the catalytic activity for electro-oxidation of hydrazine hydrate on anionic ionomer-coated catalysts was evaluated using a (4 × 4) 16-channel electrochemical electrode array in 1.0 M KOH+1.0 m hydrazin hydrate solution at 60°C.
TL;DR: In this article, an efficient, green, and facile four-component reaction for the preparation of pyrano[2,3c]pyrazole derivatives through the condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate or phenyl hydride under aqueous condition is reported.
Abstract: Article history: Received March 20, 2013 Received in Revised form July 7, 2013 Accepted 10 July 2013 Available online 12 July 2013 An efficient, green, and facile four-component reaction for the preparation of pyrano[2,3c]pyrazole derivatives through the condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate or phenyl hydrazine in the presence of commercially available organocatalyst sodium benzoate under aqueous condition is reported. The products are produced with high yields and in shorter reaction times. It also is mild, safe, green and environmental friendly. © 2013 Growing Science Ltd. All rights reserved.
27 Oct 2013
TL;DR: In this article, Ni-based catalysts, including binary Ni 0.8Zn 0.2 and Ni0.9La 0.1, were investigated for hydrazine oxidation in direct hydrazin hydrate fuel cell anodes by a temperature controlled 16-channel electrochemical combinatorial array.
Abstract: Abstract Ni-based catalysts, binary Ni–M (with M = Mn, Fe, Zn, La) and ternary Ni–Mn–Fe and Ni–Zn–La were investigated for hydrazine oxidation in direct hydrazine hydrate fuel cell anodes by a temperature controlled 16-channel electrochemical combinatorial array. The binary Ni0.8Zn0.2 and Ni0.9La0.1 catalysts are significantly more active than the Ni reference catalyst for hydrazine oxidation. While the best Ni0.8Zn0.1La0.1 ternary catalyst is close to the high active binary catalysts in composition. Additionally, Ni0.6Fe0.2Mn0.2 catalysts also showed high catalytic activity for hydrazine oxidation in alkaline media over standard Ni catalyst. The X-ray diffraction (XRD) analysis indicated that the alloying effect between Ni and added elements improves the catalytic activity for hydrazine oxidation. As a result of the screening tests and our previous research, unsupported binary Ni0.87Zn0.13 and Ni0.9La0.1 catalysts were synthesized by spray pyrolysis and tested in a direct hydrazine hydrate fuel cell MEA (DHFC) producing 486 mW cm−2 and 459 mW cm−2, respectively.
TL;DR: An anti-Bredt N-heterocyclic carbene gold(I) chloride complex was synthesized by taking advantage of the reversible insertion of the free carbene into the NH bond of hexamethyldisilazane to promote the parent hydrazine hydroamination of terminal alkynes at room temperature.
TL;DR: In this paper, a coumarin-based chromogenic and ratiometric probe for hydrazine was presented, which could selectively detect hydrazines via an intramolecular charge transfer (ICT) mechanism with a red-shift of 21 nm.
Abstract: A coumarin-based chromogenic and ratiometric probe for hydrazine was presented, which could selectively detect hydrazine via an intramolecular charge transfer (ICT) mechanism with a red-shift of 21 nm. Importantly, the probe could selectively detect hydrazine over other primary amines.
TL;DR: Solid supported platinum(0) (SS-Pt) nanoparticles were developed as a heterogeneous catalyst following a reduction/deposition method and characterized by SEM, TEM, EDX and XRD analysis.